Curtain walls are generally used and applied in modern building constructions and are the outer covering of said constructions in which the outer walls are non-structural, but merely keep the weather out and the occupants in. Curtain walls are usually made of a lightweight material, reducing construction costs and weight. When glass is used as the curtain wall, a great advantage is that natural light can penetrate deeper within the building.
A curtain wall generally transfers horizontal wind loads that are incident upon it to the main building structure through connections at floors or columns of the building. Curtain walls are designed to resist air and water infiltration, sway induced by wind and seismic forces acting on the building and its own dead load weight forces. Curtain walls differ from storefront systems in that they are designed to span multiple floors, and take into consideration design requirements such as thermal expansion and contraction, building sway and movement, water diversion, and thermal efficiency for cost-effective heating, cooling, and lighting in the building.
There are different types of curtain wall structures, e.g. curtain wall structures having a common curtain wall design including a foil-faced curtain wall insulation, a steel back pan design or which include glass, especially vision glass extending to the finished floor level below.
A typical curtain wall configuration comprises a profiled framework of vertical studs, so called mullions, and horizontal studs, so called transoms. The space between these profiles is filled either with glass panels within the window area or spandrel panels within the front of the floors. A common spandrel design comprises a pre-manufactured metal pan filled with insulating material. The remaining gap between spandrel and floor has to be sealed against fire, smoke and sound and withstand certain movement.
Curtain wall structures including an interior panel such as a back pan or other similar construction which can be of metal or other material extending across the interior surface of a curtain wall are common in modular designs. The interior panels of a curtain wall are generally made from a metal or insulation material which can easily bend, distort or be otherwise deformed when exposed to strong winds or elevated temperatures, such as intensive sunlight or heat, such as in the event of a fire. Bending, distorting or deforming of these interior panels can result in significant problems in attempting to maintain a complete thermal insulation and seal within the safing slots between the outer edges of the floor construction and the exterior curtain wall construction during a storm or fire. In particular, maintaining of a complete thermal insulation and seal at all time during a fire is important to prevent heat, smoke and flames from spreading from one floor to an adjacent floor. Further, it is important to prevent water infiltration as well as to inhibit water transfer within the building structures and to enhance water-tightness of the safing slot sealing system, i.e. in general it is important to enhance the water-stopping properties of the insulation and seal within the safing slot.
The gap between the floor and the interior wall surface of a curtain wall defines a safing slot, also referred to as perimeter slab edge (void) or perimeter joint, extending between the interior wall surface of the curtain wall construction and the outer edge of the floor. This safing slot is essential to slow the passage of fire and combustion gases between floors. Therefore, it is of great importance to improve fire stopping at the safing slot in order to keep heat, smoke and flames from spreading from one floor to an adjacent floor. It is important to note that the firestop at the perimeter slab edge is considered a continuation of the fire-resistance-rating of the floor slab. In general, the standard fire test method NFPA 285 provides a standardized fire test procedure for evaluating the suitability of exterior, non-load bearing wall assemblies and panels used as components of curtain wall assemblies, and that are constructed using combustible materials or that incorporate combustible components for installation on buildings where the exterior walls have to pass the NFPA 285 test.
In order to obtain certified materials, systems and assemblies used for structural fire-resistance and separation of adjacent spaces to safeguard against the spread of fire and smoke within a building and the spread of fire to or from the building, the International Building Code IBC 2012 provides minimum requirements to safeguard the public health, safety and general welfare of the occupants of new and existing buildings and structures. According to the International Building Code IBC 2012 Section 715.4, voids created at the intersection of the exterior curtain wall assemblies and such floor assemblies shall be sealed with an approved system to prevent the interior spread of fire where fire-resistance-rated floor or floor/ceiling assemblies are required. Such systems shall be securely installed and tested in accordance with ASTM E 2307 to provide an F-rating for a time period at least equal to the fire-resistance-rating of the floor assembly.
However, there is a code exception that states that voids created at the intersection of the exterior curtain wall assemblies and such floor assemblies, where the vision glass extends to the finished floor level, shall be permitted to be sealed with an approved material to prevent interior spread of fire. Such material shall be securely installed and capable of preventing the passage of flame and hot gasses sufficient to ignite cotton waste when subjected to ASTM E 119 time-temperature fire conditions under a minimum positive pressure differential of 0.01 inch of water column for the time period at least equal to the fire-resistance-rating of the floor assembly.
Although some glass and frame technologies have been developed that are capable of passing applicable fire test and building code requirements, there is hardly any system that addresses the exception stated in the International Building Code IBC 2012 Section 715.4 and fulfills the code section ASTM E 2307 full-scale testing. There are very few complicated curtain wall systems known that address above mentioned exception and at the same time comply with the requirements according to ASTM Designation: E 1399-97 (Reapproved 2005), in particular having a movement classification of class IV. Class IV is a combination of thermal, wind, sway and seismic movement types. These have been tested according to the invention in both horizontal and vertical conditions. The E 1399, Standard Test Method for Cyclic Movement and Measuring the Minimum and Maximum Joint Widths of Architectural Joint Systems, is used for simulation of movements of the ground, such as for example an earthquake, or even movements under high wind load or life load.
However, there is no system known that is used in a curtain wall structure that provides additionally a dynamic system complying with ASTM E 1399, such as for example a curtain wall structure defined by an interior wall surface, which includes an interior panel, such as a back pan, extending over the interior surface thereof and at least one floor spatially disposed from the inner wall surface, thereby sealing of the safing slot between the floor and the back pan of this curtain wall, which extends between the interior wall surface of the interior panel and the outer edge of the floor, in particular when vision glass is employed. Said safing slot is needed to compensate dimensional tolerances of the concreted floor and to allow movement between the floor and the façade element caused by load, such by life, seismic or wind load.
Further, there are a lot of sealing systems known that use only mineral wool for isolating purposes. However, mineral wool itself is not watertight and has to be coated or otherwise impregnated before employing it within a safing slot of a curtain wall structure to prevent water infiltration as well as to inhibit water transfer within the building structures and to enhance water-tightness of the sating slot sealing system. Therefore, there is a need for alternative safing slot filling system, which addresses the above and hence, enhances the water-stopping properties of the insulation and seal within the safing slot.
Due to the increasingly strict requirements regarding fire-resistance as well as horizontal and vertical movement, there is a need for a dynamic, thermally and acoustically insulating and sealing system for a curtain wall structure that is capable of meeting or exceeding existing fire test and building code requirements and standards including existing exceptions. In particular, there is a need for systems that prevent the spread of fire when vision glass of a curtain wall structure extends to the finished floor level below even when exposed to certain movements (complying with the requirements for a class IV movement).
Moreover, there is a need for systems that improve fire-resistance as well as sound-resistance, and have, at the same time, enhanced water-stopping properties and can be easily integrated during installation of the curtain wall structure. In particular, there is a need for dynamic, fire-resistance-rated thermally insulating and sealing systems that additionally address water infiltration as well as inhibition of water transfer within the building structures and enhance the water-tightness of the safing slot sealing system.
Further, there is a need for systems that can be easily installed within a safing slot, where, for example, access is only needed from one side, implementing a one-sided application.
Still further there is a need for systems, that can be either easily employed in a stick-built exterior dynamic curtain wall façade or used during the assembling a unitized panel for use within an exterior dynamic curtain wall assembly, making it easier for the installers to install the pre-assembled curtain wall panel on the job side.
In view of the above, it is an object of the present invention to provide a dynamic, thermally insulating and sealing system for effectively thermally insulating and sealing of a safing slot within a building construction, having a curtain wall construction defined by an interior wall surface including one or more framing members and at least one floor spatially disposed from the interior wall surface of the curtain wall construction.
Still further, it is an object of the present invention to provide a full-scale ASTM E 2307 as well as ASTM E 1399 tested system for floor assemblies, especially where the vision glass extends to the finished floor level, to address the code exception, to avoid letters and engineering judgments, and to secure and provide defined/tested architectural detail for this application, in particular, by providing a tested system for fire- as well as movement-safe architectural compartmentation.
Still further, it is an object of the present invention to provide a system that can be easily installed within a safing slot, where, for example, access is only needed from one side, implementing a one-sided application.
Still further, it is an object of the present invention to provide a system that can be employed in a stick-built exterior dynamic curtain wall façade or used in assembling a unitized panel for use within an exterior dynamic curtain wall.
Still further, it is an object of the present invention to provide a system that has improved fire-resistance as well as sound-resistance, and has at the same time enhanced water-stopping properties and can be easily integrated during installation of the curtain wall structure. Further, the object is to provide a fire-resistance-rated thermally insulating and sealing system that additionally addresses water infiltration as well as inhibition of water transfer within the building structures and enhancement of water-tightness of the safing slot sealing system.
These and other objectives as they will become apparent from the ensuring description of the invention are solved by the present invention as described in the independent claims. The dependent claims pertain to preferred embodiments.